Radiology, Vol 203, 115-119, Copyright © 1997 by Radiological Society of North America
Zebra pattern: a diagnostically challenging hepatic parenchymal enhancement pattern at CT arterial portography
JA Lawrance, VG McDermott, EK Paulson, MT Keogan, DM Delong, WC Meyers and RC Nelson
Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
PURPOSE: To investigate the effect of arterial injection site and splenic
volume on the hepatic zebra pattern seen at computed tomographic (CT)
arterial portography. MATERIALS AND METHODS: Images from CT arterial
portographic examinations, performed via either the splenic artery (SA)(n =
47) or superior mesenteric artery (SMA)(n = 51) in 98 patients, were
reviewed. The hepatic parenchymal enhancement pattern was assessed by three
blinded reviewers. Splenic volume was determined. RESULTS: Twenty-two of 98
(22%) CT arterial portographic studies showed a zebra pattern: 10 of 47
(21%) with injection via the SA and 12 of 51 (24%) with injection via the
SMA. The mean percentage of hepatic parenchyma with nontumorous perfusion
defects was 55% with the zebra pattern versus 12% without (P < .001).
For SA injections, the mean splenic volume was lower in patients with the
zebra patterns (321 vs 409 cm3, P = .09). For SMA injections, it was higher
in patients with zebra patterns (372 vs 291 cm3, P = .10). CONCLUSION: The
zebra pattern can cause difficulties in interpreting images. It is due to
alternating, well-defined regions of portal venous hyper- and
hypoperfusion; it likely has a multifactorial cause and is likely due to
technical parameters such as the injection site, the volume of the spleen,
and the hemodynamic effects of the tumor.
